Block-level element bindings not updating when visibility is hidden or collapsed (in Firefox)

[sxxov]

Describe the bug

What is expected:

• Block-level element bindings (clientHeight, clientWidth, offsetHeight, offsetWidth) update regardless of visibility & browser.

What happens instead:

• On Firefox (tested on stable 91.0.2 & dev 92.0b9), they update only when visibility is not hidden or collapsed.
• On Chrome (tested on stable 92.0.4515.159 & dev 95.0.4630.1) & Edge (tested on stable 93.0.961.38), they update regardless of visibility's value.

Reproduction

https://svelte.dev/repl/bacc64f09063438db938745594c69d4c?version=3.42.4

Logs

No response

System Info

System:
    OS: Windows 10 10.0.19043
    CPU: (16) x64 AMD Ryzen 9 4900HS with Radeon Graphics
    Memory: 3.00 GB / 15.42 GB
  Binaries:
    Node: 14.17.5 - C:\Program Files\nodejs\node.EXE
    npm: 6.14.14 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1023.0), Chromium (93.0.961.38)
    Internet Explorer: 11.0.19041.906

Severity

annoyance

[sxxov]

For any passerbys, you may replace visibility: hidden/collapsed with:

opacity: 0;
pointer-events: none;

[Prinzhorn]

Another edge case, related

https://bugzilla.mozilla.org/show_bug.cgi?id=1295245
#4233
#6127
#5524

[sxxov]

https://bugzilla.mozilla.org/show_bug.cgi?id=1295245

"Opened 5 years ago"

The bug's old enough to go to kindergarten. I guess we'll just have to deal with it for now.

[Rich-Harris]

It looks like this was fixed in Firefox at some point — the REPL above works, and it works in Svelte 5, so I'll close this